This is because of the natural twist out on the feet.
Some rigs have the feet straight on, other rigs have the feet twisted out. In retrospect I should have insisted that the feet be pointing straight forward on this rig, but it’s too late now. Oh well, but it is a common problem that you will need to learn to overcome, so it isn’t a bad thing in the end.
There isn’t an easy quick fix, but you can copy the x value from the first frame of contact, and then paste that x value on each of the other steps (first contact). Then repeat this for the last frame of contact. I hope that makes sense, Eric.